Update composable guide reset values (#2511)

* update

* update

Author: devloos

src/guide/reusability/composables.md

@@ -216,16 +216,19 @@ export function useFetch(url) {
   const data = ref(null)
   const error = ref(null)
 
-	const fetchData = (dt) => {
-			fetch(toValue(url))
+  const fetchData = () => {
+    // reset state before fetching..
+    data.value = null
+    error.value = null
+
+    fetch(toValue(url))
       .then((res) => res.json())
       .then((json) => (data.value = json))
       .catch((err) => (error.value = err))
-	}
+  }
 
   watchEffect(() => {
-    // reset state before fetching..
-    fetchData(url)
+    fetchData()
   })
 
   return { data, error }